The present invention relates to a vacuum processing apparatus; and more particularly, the invention relates to a vacuum processing apparatus which is suitable for performing treatment, such as etching, chemical vapor deposition (CVD), spattering, ashing, rinsing or the like, on a sample of a semiconductor substrate, such as a Si substrate, and to a semiconductor manufacturing line for manufacturing semiconductor devices using the vacuum processing apparatus.
Basically, a vacuum processing apparatus is composed of a cassette block and a vacuum processing block. The cassette block has a front facing the bay path of the semiconductor manufacturing line and extending toward the longitudinal direction of the semiconductor manufacturing line, an alignment unit for aligning the orientation of a cassette for a sample or the orientation of a sample, and a robot operating under an atmospheric pressure environment. The vacuum block has a load lock chamber in the loading side, a load lock chamber in the unloading side, a processing chamber, a post treating chamber, a vacuum pump and a robot operating under a vacuum environment.
In the vacuum processing apparatus, a sample extracted from the cassette in the cassette block is transferred to the load lock chamber of the vacuum processing block by the atmospheric transfer robot. The sample is further transferred to the processing chamber from the load lock chamber by the atmospheric transfer robot and is set on an electrode structure body to be subjected to processing, such as plasma treatment. Then, the sample is transferred to the post treating chamber to be processed, if necessary. The sample having been processed is transferred to the cassette in the cassette block by the vacuum transfer robot and the atmospheric transfer robot.
Vacuum processing apparatuses for performing plasma etching on a sample are disclosed, for example, in Japanese Patent Publication No. 61-8153, Japanese Patent Application Laid-open No. 63-133532, Japanese Patent Publication No. 6-30369, Japanese Patent Application Laid-Open No. 6-314729, Japanese Patent Application Laid-Open No. 6-314730, and U.S. Pat. No. 5,314,509.
In the above-referenced conventional vacuum processing apparatuses, the processing chambers and the load lock chambers are concentrically arranged or arranged in rectangular shape. For example, in the apparatus disclosed in U.S. Pat. No. 5,314,509, a vacuum transfer robot is arranged near the center of the vacuum processing block with three processing chambers being concentrically arranged around the vacuum transfer robot, and a load lock chamber in the loading side and a load lock chamber in the unload side are provided between the vacuum transfer robot and the cassette block. In these apparatuses, there is a problem in that the required installation area of the whole apparatus is large since the rotating angles of the transfer arms of the atmospheric transfer robot and the vacuum transfer robot are large.
On the other hand, the processing chamber in the vacuum processing block and the vacuum pump and other various kinds of piping components of the vacuum processing apparatus require maintenance, such as scheduled and unscheduled inspection or repairing. Therefore, in general, there are provided doors around the vacuum processing block so that inspection and repairing of the load lock chamber, the un-load lock chamber, the processing chamber, the vacuum transfer robot and the various kinds of piping components can be performed by opening the doors.
In the conventional vacuum processing apparatus, there is a problem in that the installation area is large even though the sample to be handled has a diameter d smaller than 8 inches (nearly 200 mm) and the outer size of the cassette Cw, is nearly 250 mm. Further, in the case of handling a large diameter sample having a diameter d above 12 inches (nearly 300 mm), the size of the cassette Cw, becomes nearly 350 mm. Accordingly, the width of the cassette block containing a plurality of cassettes becomes large. If the width of the vacuum processing block is determined based on the width of the cassette block, the whole vacuum processing apparatus requires a large installation area. Considering a cassette block containing four cassettes as an example, the width of the cassette block cannot help but increase at least by nearly 40 cm when the diameter d of a sample increases from 8 inches to 12 inches.
On the other hand, in a general semiconductor manufacturing line, in order to process a large amount of samples and employ various kinds of processes, a plurality of vacuum processing apparatuses performing the same processing are gathered in a bay, and transmission of samples between bays is performed automatically or manually. Since such a semiconductor manufacturing line requires a high cleanness, the whole semiconductor manufacturing line is installed in a large clean room. An increase in the size of a vacuum processing apparatus due to an increase in diameter of a sample to be processed results in an increase in the required installation area of the clean room, which further increases the construction cost of the clean room, which by its nature already has a high construction cost. If vacuum processing apparatuses requiring a larger installation area are installed in a clean room having the same area, a reduction in the total number of the vacuum processing apparatuses or a decrease in the spacing between the vacuum processing apparatuses becomes inevitable. A reduction in the total number of the vacuum processing apparatuses in the clean room having the same area decreases the productivity of the semiconductor manufacturing line and increases the manufacturing cost of the semiconductor devices as an inevitable consequence. On the other hand, a decrease in the spacing between the vacuum processing apparatuses decreases the maintainability of the vacuum processing apparatus due to lack of maintenance space for inspection and repair.